Mobile communication devices are a part of everyday life. Users may have more than one mobile communication device, and may trade in models yearly to own those with current design trends and up-to-date functionality. Manufacturers are constantly striving to include advanced features in their mobile communication devices as well as maintain a design edge. While there is a trend toward the inclusion of more features and improvements for current features, there is also a design trend toward smaller mobile communication devices. It would be desirable while providing advanced features and maintaining an edge in design trends, to also make improvements to reduce manufacturing costs.
A popular design trend is the translucent touch screen. In for example a clam shell form factor device, a substantially transparent touch screen may be included on the flip of the device. The main display on the main housing may be viewed through the touch screen of the flip so that a user may utilize menus of the main display without placing the clam shell device in the open position. For example, the translucent touch screen may include discreet buttons or touch zones which when touched are responsive to indicia on the main display.
Indium tin oxide (ITO) has been utilized for semi-transparent capacitive touch screens. In translucent ITO touch screens, patterns are formed to provide activation points or zones on the touch screen. Typically, opaque silver ink is used to form signal traces from the activation zones to a printed circuit board (PCB) or other circuitry component linked to the controller of the device. A set of touch zones is formed by a pattern of ITO areas, separated one from another to isolate the zones from one another. In a standard touch screen size of approximately 40 mm by approximately 60 mm, an ITO touch screen may include up to eight touch zones or buttons without using opaque silver ink signal traces. Electronic components are connected to the silver ink signal traces by adhesion. Moreover, the opacity of the silver ink can detract from the translucent look of the touch screen, and often the silver ink may therefore be concealed by artwork. While semi-transparent touch screens made using ITO are gaining popularity, improvements in semi-transparent touch screens are desirable.